A common disk drive design generally includes at least one data storage disk (e.g., magnetic) with concentric data tracks, an air bearing slider for each data storage surface of each data storage disk that includes a read/write head for reading and writing data on the various data tracks on the corresponding data storage surface, an actuator arm assembly (generally including a rigid actuator arm or tip and a suspension) for holding the slider over the corresponding data storage surface, and a voice coil motor for moving the actuator arm assembly, and hence the head(s), across the corresponding data storage surface to the desired data track and holding the head over the relevant data track during a read or write operation. The air bearing slider generally flies above its corresponding data storage surface during disk drive operations on a boundary layer of air that is carried by the rotating data storage disk and that is appropriately compressed by the slider.
Disk drives increasingly reflect a need to improve the density at which information can be recorded on and reliably read from a data storage medium, e.g., a disk. The recording density of a disk drive is effectively limited by at least two factors: 1) the distance between the slider and the data storage medium during read/write operations; and 2) the wasted radial distance of the data storage surface the slider must travel during loading/unloading processes. A goal of most flying-type slider designs is to operate a slider as closely as possible to a data storage medium during normal disk drive operations, while avoiding physical impact with the data storage medium. In slider air bearing designs, a minimal amount of clearance (fly height) of the slider relative to the data storage medium is preferred so that, for example, the head can distinguish between magnetic fields emanating from adjacently spaced tracks on the data storage medium. Accordingly, most recent slider designs have implemented complimentary positive pressure-producing components (e.g., air bearing surfaces) and negative pressure producing components (e.g., a suction cavity) to minimize and control the fly height of the slider. During normal reading/writing operations, the negative pressure producing components of the slider generally tend to beneficially urge the slider toward the data storage surface to keep the fly height at a minimum. However, in unloading a slider out of operational interface with a spinning data storage medium, the negative pressure can be a hindrance that requires a significant amount of radial distance to be dissolved. Unfortunately, the radial distance of the disk surface the slider travels while the negative pressure component(s) is being dissolved generally cannot be utilized to store data. This wasted radial distance (generally known in the art as a “footprint”) of the data storage medium may result in wasting up to about 8% or more of the potential data storage surface of the disk.
A variety of disk drive and slider designs have been proposed and implemented to more quickly dissolve the negative pressure associated with wasted disk space (or “footprint”) during unload operations of load/unload-type disk drives. Specifically, the suction cavity has been positioned more toward the trailing edge of the slider. However, such a development enables the leading edge of the slider to increase its pitch during unloading which may result in slider flight instability and damage/wear to the corresponding data storage surface. Additionally, “leading edge limiters” have been utilized in an attempt to more quickly dissolve negative pressure associated with the slider. These leading edge limiters are generally attached to the load beam and tend to engage the flexure of the load beam if the slider does not unload from operative interface with the data storage surface easily. Essentially, these leading edge limiters function to jerk the slider away from the data. storage surface. However, control of such leading edge limiters has been difficult to achieve (with an ideal gap being about 30 microns having an ideal tolerance of about±10 microns, and the actual achieved gap being closer to about 65 microns having an actual tolerance undesirably closer to about±25 microns). Further, various attempts have been made to tightly control the pitch static attitude and roll static attitude of a slider, but no significant advances have been made. Notwithstanding these efforts, it would be desirable to develop a slider design which reduces the radial data storage space wasted during unloading operations of a load/unload/type disk drive.